1. Field of the Invention
The present invention relates to a card slot, and to an electronic device provided with such a card slot.
2. Description of the Related Art
A card slot for attaching an IC card (for example a PCMCIA card) to an electronic device (for example, a lap top computer or a flat-screen television) has conventionally been used. By inserting the IC card into the card slot, it is possible to connect the IC card and the electronic device.
However, recent IC cards have become highly functional (for example, having a wireless function etc.) and contain highly integrated circuitry, which means that a lot of heat is generated internally. A need has therefore arisen to radiate internally generated heat to the outside.
As technology for radiating internally generated heat of an IC card, for example, there is the technology disclosed in FIG. 2 of Unexamined Japanese patent application Hei. 10-198462 (patent document 1). With this technology, a radiator is previously arranged inside the slot. If an IC card is inserted into the inside of the slot, the radiator and the IC card are brought into contact, and heat of the IC card is radiated via the radiator.
However, with this technology, at the time of inserting the IC card there is friction between the radiator and the IC card, which means that there is the drawback that force is required to insert the IC card.
On the other hand, with technology disclosed in unexamined Japanese patent application No. 2005-222537 (patent document 2), before inserting the IC card a heatsink is retracted upwards. If the IC card is inserted, the heatsink is gradually lowered by a cam mechanism. The heatsink and the IC card are brought into contact with each other along the insertion stroke of the IC card. With this technology, at the start of insertion of the IC card, there is no resistance by the heatsink to insertion, and so insertion is smooth.
However, with this technology also, at some point during insertion of the IC card there is friction between the lower surface of the heatsink and the upper surface of the IC card, which means that insertion resistance suddenly increases once that point in time is reached. If this happens, it is conceivable that, depending on the user, they may be under the misconception that the card has been sufficiently inserted before the IC card is connected to the electronic device, and stop insertion.
The technology disclosed in unexamined Japanese patent application 2005-285522 (patent document 3), similar to the disclosure of patent document 2, also lowers a heatsink using a cam mechanism. However, with this technology, a structure to automatically lower the heat sink after the IC card has been completely inserted into the slot is adopted. By doing this, during insertion of the IC card the heat sink and the IC card do not interfere with each other, and so insertion resistance is slight. With this technology, however, a mechanism is required to independently lower the heat sink after insertion of the IC card, and there is the drawback that the structure will be made complicated and the number of components increased. These are both likely to be the cause of failure and increased cost.
Patent Publication 1:                Unexamined Japanese patent application No. Hei. 10-198462        
Patent Publication 2:                Unexamined Japanese patent application No. 2005-222537        
Patent Publication 3:                Unexamined Japanese patent application No. 2005-285522        
The present inventors are proposing a card slot in which an IC card can be easily and reliably fitted. This technology has a general structure as outlined in the following.                Cam surface moves with insertion of IC card.        Pin lowered in line with the shape of this cam surface, and plate spring attached to pin lowered.        With lowering of the plate spring, heatsink supported by plate spring lowered.        
Once above sequence of operations is completed, the lower surface of the heatsink contacts the IC card. In this way it becomes possible to radiate heat using the heatsink.
Here, the plate spring supporting the heat sink is attached by a screw to the center of the upper surface of the heat sink, at the center part of the plate spring.
In a state where this type of card slot is assembled on a substrate, there may be cases when the substrate is conveyed. For example, at a factory or the like where a heatsink with card slot attached is assembled, the place where the card slot is attached to the substrate and the place where the substrate is attached to a casing may be some distance apart. In this situation it is necessary to convey the substrate.
Here, if the substrate is dropped during conveyance, or it bumps into something, impact will be applied to the substrate. At this time, with the technology described, since the heatsink is supported by a plate spring, there is a possibility that the position of the heatsink will deviate from a predetermined position. If this type of positional deviation arises, there will be disadvantages such as it becoming difficult to incorporate the substrate into the casing.
In order to avoid this type of problem, means such as raising the strength of the spring supporting the heat sink and installing a guide member are conceivable. However, in this case it is likely that other disadvantages will arise, such as the card slot being increased in size and the weight increasing. In particular, in order to increase the thermal capacity of the heatsink and increase its contact surface area with the outside air, the heatsink often has a particular size and weight. It is therefore easy for the above-described disadvantages to arise.
The present invention has been conceived in view of the above-described situation. An object of the present invention is to provide a card slot that can improve shock resistance, and an electronic device that uses such a card slot.